Abstract 18960: Regional Effects of a Hyaluronic Acid Based Hydrogel on Circumferential Strain of the Left Ventricular Wall Post-Myocardial Infarction
Background: Myocardial infarction (MI) causes adverse left ventricular (LV) remodeling, which can be defined as MI expansion (MI thinning) and LV dilation. One treatment approach that has gained traction is the use of biomaterials, such as hydrogels, injected into the MI. However, region specific changes, such as LV strain patterns following post-MI hydrogel injections, remain to be fully understood. This study utilized cardiac MRI and harmonic phase analysis (HARP) to address this issue.
Methods/Results: MI was induced in adult pigs (coronary ligation; n=6) and randomized to MI injections (9 point-100uL injections) of a hydrogel (MI/gel, hyaluronic acid/hydroxyethyl methacrylate) or saline (MI only; same volume and injection pattern). At 14 days post-MI, LV end-diastolic volume increased from control values (n=3) by 26% in the MI only group but by only 12% in the MI/gel group (p<0.05). MI wall thickness fell from control in the MI only group (0.86±0.07 vs 0.36±0.05 cm, respectively, p<0.05) but was higher in the MI/gel group (0.53±0.2 cm). Thus, targeted gel injections attenuated indices of post-MI remodeling. MRI/HARP was performed and regional (MI and remote; posterior/anterior regions) and layer-specific (endocardial, midwall, epicardial) circumferential wall strain computed (Figure 1; LV strain maps). LV strain fields fell within the MI region in the MI only group (p<0.05 vs. control). LV strain fields, such as in the MI endocardial layer, increased towards control in the MI/gel group (p<0.05 vs. MI only).
Conclusion: The findings demonstrated the complex manner by which localized biomaterial injections impact LV wall mechanics in the post-MI context and suggest that the use of HARP can contribute to modeling/developing optimization strategies for this therapeutic approach. Figure 1: Normalized and aggregated end systolic stain fields (obtained via HARP analysis) for control, MI only, and MI/gel groups (n=3/group).
Author Disclosures: E. Romito: None. D. Peters: None. S. Thorn: None. M.R. Stacy: None. J.A. Shuman: None. H. Doviak: None. P.E. Perreault: None. J. Jacobs: None. C.B. Logdon: None. B. Purcell: None. T. Shazly: None. J.A. Burdick: None. A.J. Sinusas: Other Research Support; Significant; Merck Research Labs. F.G. Spinale: Research Grant; Significant; NIH. Consultant/Advisory Board; Modest; Boston Scientific, Novartis, Amgen, Acorda.
- © 2016 by American Heart Association, Inc.